Card type recording medium and method of preventing a false use thereof

ABSTRACT

This card type recording medium has plural types of inks which normally exhibit the same color visually but exhibit different optical characteristics under a predetermined condition provided in blocks in a desired pattern and, by breaking the blocks block by block in accordance with the used amount or other factor, is capable of recording information corresponding to the breakage state of the blocks. First information can be recorded by a pattern of arrangement of these plural types of inks and second information can be recorded in accordance with the breakage state of the blocks. The first information is a collation pattern which indicates that the card type recording medium is a genuine one. Since the plural types of inks exhibit the same color visually, it cannot be visually discerned which type of ink is used on which block, which makes it difficult to counterfeit the card by imitating this collation pattern. Besides, sicne the ink arrangement pattern cannot be visually discerned, it is difficult to repair punched holes of broken blocks by using the ink used in forming this ink arrangement pattern so that false alteration of the second information can be prevented.

This is a division of application Ser. No. 07/604769, filed on Oct. 26,1990.

BACKGROUND OF THE INVENTION

This invention relates to a card type recording medium applicable tovarious types of card type recording media including a prepaid card, anidentification card, a bank card etc. and, more particularly, to a cardtype recording medium of a type in which desired information is recordedthereon by breaking blocks arranged on the card block by block. Theinvention further relates to a method of preventing a false use of suchcard type recording medium by counterfeiting of a card or falserestoration of a broken block on a card.

Known in the art are various methods and apparatuses for detecting asurface design pattern of a bank note, bill, bond or the like in anoptical way. Japanese Patent Publication No. 1-23828, for example,discloses optical validation of a bank note or the like by utilizingdifference in absorption (or transmittance) to a visible ray andinfrared ray between a magnetic ink and a color ink. Japanese PatentApplication Laid-open No. 51-84695 discloses also an optical typevalidation apparatus for a bank note or the like based on a similarprinciple.

Known also in the art is a technique of utilizing an invisible lightsuch as infrared ray for reading of information or card identificationin a card type recording medium such as a prepaid card. Japanese PatentPublication No. 62-4756, for example, discloses a technique according towhich, in a case where proper data such as the name of the owner isrecorded by punching in an ID card or a credit card, false holes areformed with true data holes in the card, these holes are filled with apattern representing desired proper data by using an infrared raytransmitting element and an infrared ray non-transmitting element, andthe proper data is read by irradiating infrared ray. The Japanese PatentPublication No. 56-13341 discloses a technique according to which a barcode pattern is printed with ink which reacts to invisible light, whichbar code pattern cannot be recognized in appearance by visible light.Japanese Utility Model Publication No. 52-45279 discloses putting asignature on a collation card used for depositing of money in a bank orthe like purpose is made with an invisible light ink. Japanese PatentApplication Laid-open No. 64-87395 discloses providing an infrared rayreacting pattern on a magnetic recording layer of a card type recordingmedium for discriminating a true card from a false one. Japanese PatentApplication Laid-open No. 58-171995 discloses printing a bar codepattern with ink which reacts to infrared ray on a bar code recordedpari-mutuel ticket so as to prevent recognition of the pattern byvisible light in appearance. Japanese Patent Application Laid-open No.61-136188 discloses a technique according to which a magnetic cardincludes an invisible light identifying recording section in addition toa magnetic recording section, and data concerning variable and securitydata are recorded in the magnetic recording section whereas data properto the card is recorded in the invisible light identifying recordingsection.

In a card type recording medium such as a prepaid card, it has beenknown also to perform punching in a predetermined region in the card inaccordance with the used amount thereby to visibly display the usedamount i.e., the remaining amount available for future use, of the card.Japanese Patent Application Laid-open No. 63-263602, for example,discloses provision of a punched recording section in addition to amagnetic recording section in a magnetic card such as a prepaid card andrecording of the state of use by punching as well as by magneticrecording. Japanese Patent Application Laid-open No. 62-203290 disclosesforming a punched recording section with a magnetic recording medium ina prepaid card and coping with a false alteration such as closing holespunched in the card with a tape or the like by detecting holes notoptically but magnetically. Japanese Patent Application Laid-open No.64-21695 discloses a technique according to which a punched recordingsection is formed with a magnetic recording medium in a prepaid card,information concerning use of the card is previously recordedmagnetically and the used amount, i.e., the remaining amount for use,can be visually confirmed and magnetically read by breaking of blocks ofthe magnetic recording medium. Japanese Utility Model ApplicationLaid-open No. 64-17774 discloses forming a punched recording sectionwith a fluorescent material.

As to the card type recording media in which information is recorded bybreaking means such as punching among the above described prior art cardtype recording media, possibility of a false use of the card by falselyaltering information contained in the card by filling holes punched inthe card with a tape or coating has become a serious problem. For copingwith this problem of false use of the card, the above described JapaneseUtility Model Application Laid-open No. 64-17774 discloses forming thepunched recording section with a fluorescent material. This techniquehowever still has the problem that a false use cannot be detected whenthe false user has filled holes punched in the card with a fluorescentcoating of the same quality. The same problem remains unsettled withrespect to the other prior art techniques utilizing invisible light suchas infrared ray for reading of proper information in the card typerecording medium.

Further, the prior art cards in which information is recorded bybreaking means such as punching, only one type of information relying onpresence or absence of a hole punched in the card can be recorded and,therefore, the amount of recordable information is limited. Besides,guard against counterfeiting of the card per se is insufficient.

SUMMARY OF THE INVENTION

It is, therefore, an object of the invention to provide a card typerecording medium of a type in which desired information is recorded bybreaking blocks arranged on the card block by block and which is capableof increasing the amount of recordable information by enabling two typesof information to be recorded on the same card.

It is another object of the invention to provide a card type recordingmedium capable of effectively preventing a false use of the card such ascounterfeiting of the card or false alteration of a broken block byenabling such two types of information to be recorded.

It is still another object of the invention to provide a method ofpreventing such false use of a card type recording medium.

The card type recording medium according to the invention ischaracterized in that it has plural types of ink which normally exhibitthe same color visually but exhibit different optical characteristicsunder a predetermined condition provided in blocks in a desired patternand, by breaking the blocks of ink block by block, is capable ofrecording information corresponding to the breakage state of the blocks.

It is an important feature of the invention that, in a card typerecording medium having plural types of inks which normally exhibit thesame color visually but exhibit different optical characteristics undera predetermined condition provided in blocks in a desired pattern, firstinformation can be recorded by the pattern of plural types of inks and,further second information corresponding to the breakage state of theblocks can be recorded by breaking the plural blocks block by block.

As an example of such ink, plural types of inks which are visually ofthe same color at normal temperature but exhibit different opticalcharacteristics to light of an invisible wavelength region. For example,ink which reacts to infrared ray and ink which does not are used incombination. For another example, ink which changes color with variationof temperature may be used.

For preventing a false use by counterfeiting of a card, it is preferablethat the arranged pattern of the plural types of inks should be acollation pattern for verifying that the card type recording medium is atrue recording medium. Since the plural types of inks are of the samecolor visually, what type of ink is used in a particular block cannot bevisually discerned, so that it is difficult to counterfeit a card byimitating the ink arrangement pattern of the true card.

As regards false alteration of information corresponding to the breakagestate of a block, since the plural types of inks are of the same colorvisually, what type of ink is used in a particular block cannot bevisually discerned, so that it is difficult to repair a broken block byusing the ink used in the ink arrangement pattern (e.g., filling thebroken block with this ink) and, as a result, a false use of the cardcan be prevented. The information recorded by the breaking of the blockmay, for example, be information concerning variable representing stateof use of the card type recording medium. Depending upon the purpose ofuse, this information may also be proper information representing, forexample, the name of user of the card type recording medium.

A method of preventing a false use of a card type recording mediumaccording to the invention comprises executing, when the card typerecording medium has been inserted, a first step of irradiating a beamof light on each block under the predetermined condition and receivingits reflected or transmitted light thereby to obtain a detection signalresponsive to the characteristic of each of the blocks, a second step ofpreparing a reference level corresponding to presence or absence of thebreakage of blocks for each of the plural types of inks and comparingthe reference level with the detection signal, and a third step ofdetecting, on the basis of result of the comparison made in the secondstep, the type of ink provided in the block and presence or absence ofbreakage of the block and collating whether or not the detected ink typepattern of the block coincides with the predetermined pattern, andprohibits use of a card type recording medium for which a result ofcollation indicating coincidence of the detected ink pattern with thepredetermined pattern in the third step has not been produced.

According to the method of preventing a false use of the card typerecording medium of the invention, in the first step, a detection signalcorresponding to the characteristic of each block is obtained byirradiating a beam of light under the predetermined condition (e.g., abeam of light of a predetermined invisible wavelength region) andreceiving its reflected or transmitted light. In the second step, areference level corresponding to presence or absence of the breakage ofblock for each of the plural types of inks is prepared and thisreference level is compared with the detection signal.

Assuming, for example, that there are two types of inks A and B, areference level Vrefa for absence of breakage concerning the ink A, areference level Vrefal for presence of breakage concerning the ink A, areference level Vrefb for absence of breakage concerning the ink B and areference level Vrefbl for presence of breakage concerning the ink B arerespectively prepared. Since the optical characteristics of therespective inks are different under the predetermined condition, thereference levels Vrefa and Vrefb during the absence of breakage differbetween the inks. Further, since the remaining amount of ink in theparticular blocks of the respective inks differs with presence andabsence of breakage, the reference levels Vrefa, Vrefal, Vrefb andVrefbl differ one from another. Accordingly, by comparing thesereference levels with the detection signal, the type of ink provided ineach of the particular block and presence or absence of breakage of theblock can be detected.

In the third step, the type of ink provided in the block and presenceand absence of breakage of the block are detected on the bias of resultof the comparison made in the second step and collation is made todetect whether or not the detected ink type pattern of the blockcoincides with the predetermined pattern. In other words, the type ofink provided in the block is detected by detecting whether or not thelevel of the detection signal from this block satisfies the condition ofthe reference level during presence or absence of breakage of thepredetermined ink provided in the block, and collation is made to findwhether or not the thus detected ink type pattern coincides with thepredetermined pattern. Presence or absence of breakage can be found bydetermining which of the conditions of the reference levels duringpresence and absence of breakage of the predetermined ink has beensatisfied.

When a result of collation indicating coincidence of the detected inkpattern with the predetermined pattern in the third step has not beenobtained, use of the card type recording medium is prohibited, becausein this case some false alteration is considered to have been made inthe card type recording medium.

In one aspect of the invention, a method of preventing a false use of acard type recording medium further comprises, providing a recording areaof a magnetic recording medium in the above described card typerecording medium and executing, upon insertion of the card, a first stepof breaking the blocks block by block in accordance with use of the cardand recording information representing use of the card in response tothe state of breakage of the block and also magnetically recording theinformation representing use of the card in the recording area of themagnetic recording medium, a second step of reading the state of the userecorded in the recording area consisting of the magnetic recordingmedium, a third step of irradiating a beam of light on the respectiveblocks under the predetermined condition and receiving its reflected ortransmitted light thereby to obtain a detection signal corresponding tothe characteristic of each of the blocks, a fourth step of preparing areference level corresponding to presence or absence of breakage ofblock for each of the plural types of inks and comparing the referencelevel with the detection signal, a fifth step of detecting, on the basisof result of comparison made in the fourth step, the type of inkprovided in the block and presence or absence of breakage of the block,collating whether or not the detected ink type pattern of the blockcoincides with the predetermined pattern, and obtaining informationindicating the state of use of the card in response to the broken stateof the block, and a sixth step of allowing use of the card when a resultof collation indicating coincidence of the detected ink pattern with thepredetermined pattern in the fifth step has been produced and alsocoincidence between the information indicating the state of use obtainedin the second step and the information indicating the state of useobtained in the fifth step has been produced.

According to the method of preventing a false use of a card typerecording medium, in the first step, information representing use of thecard is recorded magnetically in the recording area of the magneticrecording medium in the card type recording medium and also by breakageof a block in the arrangement of the plural blocks. In the second step,the information representing the state of use recorded in the recordingarea of the magnetic recording area is read and, in the third step, anoptical detection of the arrangement of the plural blocks is made and adetection signal corresponding to the characteristic of each of theblocks thereby is obtained.

In the fourth and fifth steps, in the same manner as described before,collation is made to detect whether or not the ink type pattern of eachblock coincides with the predetermined pattern on the basis of a resultof comparison of each reference level with the detection signal andpresence or absence of breakage of each block is detected andinformation indicating the state of use of the card is obtained inresponse to the breakage state of the block.

Finally in the sixth step, when a result of collation indicatingcoincidence of the detected ink pattern with the predetermined patternin the fifth step has been produced and also coincidence between theinformation indicating the state of use obtained in the second step(information recorded magnetically) and the information indicating thestate of use obtained in the fifth step (information obtained bybreakage of the blocks block by block) has been produced, use of thecard is allowed.

This method presupposes use of a card of a type such as a prepaid cardin which the used amount of the card, i.e., the remaining amountavailable for use of the card, is recorded and allows use of the cardwhen not only coincidence of the ink pattern with the predeterminedpattern but also coincidence between the two types of information of thestate of use obtained by the two different recording methods have beenproduced whereby prevention of a false use of the card can be furtherensured.

Preferred embodiments of the invention will be described below withreference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings,

FIG. 1 is in a plan view of a card type recording medium according tothe invention;

FIG. 2 is a graph showing an example of reflection characteristics oftwo types of inks A and B used in the card of FIG. 1;

FIG. 3 is a side view schematically showing an example of an opticaltype detection system for irradiating infrared ray on an arrangement ofblocks in the card of FIG. 1 to receive its reflected light and therebydetecting the level of the received light;

FIG. 4 is a graph showing a typical example of a detection signalobtained from the arrangement of blocks of the card of FIG. 1 by thedetection system of FIG. 3;

FIGS. 5 to 8 are graphs showing examples of detection signals obtainedin a case where the arrangement of blocks in the card of FIG. 1 has beencounterfeited or falsely altered; and

FIG. 9 is a block diagram showing schematically an example of a cardinformation read/write system used in carrying out the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 is a plan view of an example of the card type recording mediumaccording to the invention. A card 1 has plural types of ink whichnormally exhibit the same color visually but exhibit different opticalcharacteristics to light of an invisible wavelength region provided inblocks B1 to Bn in a desired pattern and, by breaking the blocks of inkblock by block, is capable of recording information corresponding to thebreakage state of the blocks. For example, there are two types of inks Aand B. The ink A has a small rate of reflection and the ink B has alarge rate of reflection to infrared ray. Since the two types of inks Aand B are of the same color visually, they cannot be distinguished fromeach other visually. In the figure, reference characters A and B areaffixed in the blocks to illustrate the ink arrangement pattern. Forconvenience of explanation, the ink arrangement pattern is described asthe blocks A and B being arranged alternately but the arrangement of theblocks A and B is of course not limited to the illustrated pattern.

In this example, this ink arrangement pattern is utilized as a collationpattern for verifying that the card 1 is genuine. The ink arrangementpattern however is not limited to this example but, depending upon thepurpose of use of the card, information proper to each card (e.g.,information concerning the user) may be expressed by this inkarrangement pattern.

In this example, it is assumed that this card 1 is a prepaid card andthe information recorded in accordance with the breakage state of theblocks B1 to Bn by breaking the blocks B1 to Bn block by block isinformation concerning variable (hereinafter referred to as "variableinformation") such as information representing the state of use of thecard 1. The information however is not limited to this but it may beinformation proper to each card (e.g., information concerning the user).Breaking of the blocks B1 to Bn can be effected by punching requiredblocks in the known manner.

In this example, the card 1 further has a recording area consisting of amagnetic recording medium, i.e., a magnetic stripe 2. In this magneticstripe 2, variable information representing the state of use is recordedand other suitable information such as information proper to each card(e.g., information concerning the user) may be recorded in the knownmanner.

FIG. 2 shows an example of reflection characteristics of the inks A andB. In the figure, solid lines a and b indicate reflection levels ofblocks corresponding to the inks A and B available when the blocks arenot punched and dotted lines a1 and b1 indicate reflection levels ofblocks corresponding to the inks A and B available when the blocks arepunched. It will be noted that the two reflection levels do not exhibitmuch difference to visible light but they exhibit much difference toinfrared ray.

FIG. 3 is a side view schematically showing an example of an opticaltype detection system which receives reflected light when infrared rayhas been irradiated on the blocks B1 to Bn in the card 1 and therebydetects the level of the received light. A beam of infrared ray isirradiated from an infrared ray source 3 on the blocks B1 to Bn in thecard 1 and its diffused reflection is focused by an optical system 4 andreceived by a light receiving element 5 and converted to an electricsignal. In this case, the amount of reflection of infrared ray is largerin the blocks of the ink B than in the blocks of the ink A, as shown inFIG. 2. In the case where a punched hole 6 is formed in the card 1, theamount of diffused reflection received by the light receiving element 5is reduced and the level of received light is thereby reduced. Theillustrated optical type detection system generally is fixed and theinserted card 1 itself is moved for effecting sequential scanning of theblocks B1 to Bn to sequentially detect characteristics of these blocksB1 to Bn. This optical type detection system per se is known so thatdetailed description thereof will be omitted.

FIG. 4 shows a typical example of detection signals obtained from theblocks B1 to Bn. In the figure, the coordinate represents the level ofthe detection signals and the abscissa represents time and the blocks B1to Bn are sequentially scanned in this order. In this case, is assumedthat the two types of inks A and B are arranged alternately as describedbefore. In this example, there is no ink A or B at the border ofadjacent blocks and a smooth surface of the card 1 is exposed.Accordingly, the level of reflected light from the border of theadjacent blocks becomes maximum but this level is irrelevant to therequired detection. The solid lines indicate that the block is notbroken (i.e., the block is not punched) and the dotted lines indicatethat the block is broken (i.e., the block is punched). As will beapparent from the characteristics of FIG. 2, the magnitudes of thereflected lights are in the order that the level of reflected light fromthe block corresponding to the ink B which is not punched is thelargest, the reflected light from the block corresponding to the ink Bwhich is punched is the smallest, the reflected light from the blockcorresponding to the ink A which is not punched is the third and thereflected light from the block corresponding to the ink A which ispunched is the fourth.

As described in the foregoing, the level of reflected light corresondingto presence or absence of breakage of a block differs depending upon thetype of ink. Therefore, by preparing reference levels Vrefa, Vrefa1,Vrefb and Vrefb1 corresponding to presence and absence of breakage foreach type of ink and comparing these reference levels with the detectionsignal obtained by the light receiving element 5, collation of thearrangement patterns of the inks A and B and detection of presence orabsence of a punched hole can be achieved.

For example, Vrefa represents the reference level for absence ofbreakage concerning the ink A, Vrefa1 the reference level for presenceof breakage concerning the ink A, Vrefb the reference level for absenceof breakage concerning the ink B and Vrefb1 the reference level forpresence of breakage concerning the ink B and there is relationVrefb>Vrefb1>Vrefa>Vrefa1. The detection is made on the standard that:when the level RL of the detection signal is Vrefb>RL>Vrefb1, thedetection signal represents the ink B in the absence of breakage; whenthe level RL is Vrefb1>RL>Vrefa, the detection signal represents the inkB in the presence of breakage; when the level RL is Vrefa>RL>Vrefa1, thedetection signal represents the ink A in the absence of breakage; andwhen the level RL is Vrefa1>RL, the detection signal represents the inkA in the presence of breakage. The standard of detection however is notlimited to this but it may be suitably determined.

By determining the standard of detection suitably, the type of inkprovided in each block and presence or absence of breakage of the blockcan be detected on the basis of a result of comparison. By collatingwhether or not the detected pattern of the types of inks provided in therespective blocks coincides with the predetermined ink arrangementpattern, validation of the inserted card 1 can be realized.

In a case, for example, where a card has been counterfeited by coatingblocks B1 to Bn with substantially the same ink as the ink A, levels ofdetection signals from respective blocks in the absence of breakagebecome as shown in FIG. 5. The levels RL of detection signals of allblocks become Vrefa>RL>Vrefa1 whereby it is readily detected that theink A is provided in all blocks B1 to Bn. It is therefore readily foundthat the detected pattern does not coincide with the predetermined inkarrangement pattern and, in this case, the inserted card 1 is returnedas a counterfeited card and its use is prohibited.

For another example, in a case where a card has been counterfeited bycoating blocks B1 to Bn with ink which is substantially the same as theink B, levels of detection signals from the respective blocks in theabsence of breakage become as shown in FIG. 6. In this case, the levelsRL of all detection signals become Vrefb>RL>Vrefb1 and, therefore, it isreadily detected that the ink B is provided in all blocks B1 to Bn. Itis readily found that the detected pattern does not coincide with thepredetermined ink arrangement pattern and the inserted card 1 isreturned as a counterfeit card and its use is prohibited.

Next, description will be made about a case where a card 1 having someblocks punched in accordance to use of the card has been falsely alteredby filling the punched holes with ink.

Assume, for example, that all punched blocks have been filled with theink A. In this case, levels of detection signals of the respectiveblocks become as shown in FIG. 7. The blocks which were originallyprovided with the ink A are detected as blocks without punched holes butthe blocks which were originally provided with the ink B are notdetected as normal blocks with punched holes or without punched holes sothat abnormality is detected. This abnormality can be detected because,when the punched hole of the block in which the ink B was originallyprovided has been filled with the ink A, the level of reflected lightwhich is the same as when the entire surface of the block is providedwith the ink B cannot be obtained but the level of reflected lightbecomes lower than that.

In the case of FIG. 7, when the punched hole in the block which wasoriginally provided with the ink B is filled with the ink A, the levelRL of the reflected light detection signal is not Vrefb>RL>Vrefb1 butVrefb1>RL>Vrefa. Accordingly, this block is not detected as a blockprovided with the ink B having no punched hole but is detected as ablock having a punched hole, so that the false alteration of the card isnot successful. In the illustrated example, the false alteration ofpunched holes can be detected but whether the ink arrangement pattern istrue or false cannot be detected since the ink arrangement pattern inthis case becomes the same pattern as when a block provided with the inkB has been punched. It is however possible to detect not only a falserepair of a punched hole but also a false ink arrangement pattern bysuitably determining the standard level of detection. Besides, it isusually difficult to coat ink strictly on the portion of a punched holeonly and ink is actually coated on a portion surrounding the punchedhole. In this case, as shown in FIG. 5, the entire levels fall so thatthe ink arrangement pattern can be accurately detected. Normally, falsealteration of use state information record data by punched holes is madetogether with false alteration of use state information record data inthe magnetic stripe 2. In that case, false alteration of the record bybreaking of blocks cannot be successfully achieved as described above,even if the false alteration of magnetically recorded data is madesuccessfully. Therefore, by collating whether there is coincidencebetween the two recorded data, non-coincidence can be detected. The cardin which this non-coincidence has occurred therefore is returned and itsuse is prohibited.

Assume again, for example, that all punched blocks have been filled withthe ink B. In this case, levels of detection signals of the respectiveblocks become as shown in FIG. 8. The blocks which were originallyprovided with the ink B are detected as blocks without punched holes butthe blocks which were originally provided with the ink A are notdetected as normal blocks with punched holes or without punched holes sothat abnormality is detected. This abnormality can be detected because,when the punched hole of the block in which the ink A was originallyprovided has been filled with the ink B, the level of reflected lightwhich is the same as when the entire surface of the block is providedwith the ink A cannot be obtained but the level of reflected lightbecomes higher than that.

In the case of FIG. 8, when the punched hole in the block which wasoriginally provided with the ink A is filled with the ink B, the levelRL of the reflected light detection signal is not Vrefa>RL>Vrefa1 butVrefb1>RL>Vrefa. Accordingly, this block is not detected as a blockprovided with the ink A having no punched hole but is detected as ablock having a punched hole, so that the false alteration of the card isnot successful. Accordingly, false alteration of the recorded data canbe detected and the card is returned and its use is prohibited.

Summing up, on the basis of reading of information from the blocks B1 toBn for recording by punching, validation of the card 1 can be made inthe following steps.

Respective reference levels Vrefa, Vrefa1, Vrefb and Vrefb1 are comparedwith the reflected light detection signal.

Then, on the basis of a result of this comparison, the type of inkprovided in the blocks B1 to Bn and presence or absence of breakage ofthese blocks are detected and the detected ink type pattern of eachblock is collated with the predetermined pattern to detect coincidencetherebetween.

As a result of this collation, a card 1 from which a result of collationthat the detected pattern coincides with the predetermined pattern hasnot been obtained is prohibited from use whereby a false use of acounterfeit card can be prevented.

In a case where use state information is recorded not only by the blocksB1 to Bn for recording by punching but also by the magnetic stripe 2,false alteration of the card 1 can be detected in the following manner.

Reference levels Vrefa, Vrefal, Vrefb and Vrefbl are compared with thereflected light level detection signal.

Then, on the basis of a result of comparison, the type of ink providedin blocks B1 to Bn and presence or absence of breakage are detected. Theink type pattern of the detected block is collated with thepredetermined pattern to detect coincidence therebetween and informationrepresenting the state of use is obtained in accordance with thebreakage state of the block.

When a result of collation that the detected pattern coincides with thepredetermined pattern has been obtained and coincidence between theinformation representing the state of use obtained in accordance withthe breakage state of the block and the information representing thestate of use recorded magnetically has been produced, use of the card 1is allowed. Otherwise, existence of false alteration is assumed and useof the card 1 is prohibited.

FIG. 9 shows schematically an example of the card information read/writesystem used in carrying out the invention.

Upon insertion of a card 1, a card conveying motor 11 is rotatedforwardly by the control by a CPU 10 and the card 1 thereby is fedinwardly. In this process, information recorded on the card 1 is read bythe optical type detection system shown in FIG. 3 and a magnetic sensor12. The reflected light level detection signal provided from a lightreceiving element 5 is applied to comparators 14 through an amplifier 13and compared with reference levels Vrefa, Vrefal, Vrefb and Vrefbl.Results of comparison are applied to a determination circuit 15. On theother hand, the magnetic sensor 12 reads recorded information in themagnetic stripe 2 of the card 1. The read magnetic recorded informationis supplied to the determination circuit 15 through an amplifier 16 anda waveform extracting circuit 17.

The determination circuit 15 has reference data of the ink arrangementpattern in the blocks B1 to Bn and detects the ink arrangement patternof the inserted card 1 on the basis of results of comparison from thecomparators 14 to detect whether or not the detected ink arrangementpattern coincides with the reference ink arrangement pattern. Dependingupon whether the ink arrangement pattern is genuine or not, a controlsignal is supplied from the CPU 10 to the card conveying motor 11. Ifthe ink arrangement pattern is false, the motor 11 is rotated reverselyto return the card 1 to prohibit its use.

The determination circuit 15 detects also presence or absence ofbreakage of the blocks B1 to Bn on the basis of results of comparisonfrom the comparators 14 and the reference data of ink arrangementpattern of the blocks B1 to Bn and thereby obtains informationrepresenting the state of use corresponding to the breakage state of theblocks. The determination circuit 15 also reads the informationrepresenting the state of use recorded in the magnetic stripe 2 andother information on the basis of output of the waveform extractingcircuit 17. The determination circuit 15 then collates whether there iscoincidence between the information representing the state of userecorded in the magnetic stripe 2 and the information representing thestate of use based on the breakage state of the blocks. If there is nocoincidence between the two information representing the state of use,false alteration is assumed to exist in the card 1 and a control signalis supplied from the CPU 10 to the card conveying motor 11 to rotate themotor 11 reversely. The card 1 is thereby returned and its use isprohibited.

If the ink arrangement pattern has been detected to be genuine andcoincidence between the two information representing the state of usehas been detected, the motor 11 continues its forward rotation until thecard 1 has reached a predetermined card retention position, the card 1is temporarily retained at this retention position and then use of thecard 1 is allowed.

A card use allowing signal is supplied with information representing theremaining amount and other information to a use control circuit 18. Inresponse to these information, the use control circuit 18 startspredetermined operations such as vending. Upon completion of thepredetermined operations such as vending, a signal is supplied to amagnetic head 20 and a punching device 21 to rewrite the use stateinformation in the magnetic stripe 2 and, when necessary, punch requiredblocks.

In the above described embodiment, a detection system utilizingreflected light is adopted. Alternatively, a detection system utilizingtransmitted light may be adopted.

The place on which the ink is disposed is not limited to the surface ofthe card but it may be in the middle layer of the card 1. In this case,the detection system becomes one utilizing transmitted light.

As the plural types of inks which are of the same color visually in anormal state but exhibit different optical characteristics, not onlythose used in the above described embodiment which exhibit differentcharacteristics to light of an invisible wavelength region but pluraltypes of inks which change their color with temperature (i.e.,temperature exhibiting coating) may be used. For example, ink which isof the same color visually at room temperature but changes its color ata predetermined high (or low) temperature is used as the ink B and inkwhich does not change its color with temperature is used as the ink A. Aheating device (or a cooling device) is attached to the device readinginformation on the card so that heating (or cooling) will be made indetecting presence or absence of blocks.

As described in the foregoing, according to the invention, plural typesof inks which cannot be distinguished from each other visually in anormal state are provided in a desired pattern on a card type recordingmedium and, since this pattern cannot be visually discriminated, a falseuse of the card by counterfeiting or false alteration of recorded datacan be effectively prevented. Besides, since two types of informationcan be recorded by the invisible ink arrangement pattern in the blockarrangement and by breaking of the blocks block by block, the amount ofrecordable information can be increased.

What is claimed is:
 1. A system for use with a card type recordingmedium which comprises plural types of inks that normally exhibit thesame color visually but exhibit different optical characteristics undera predetermined condition, said plural types of inks being provided inrespective blocks in a desired block pattern, said desired block patternrepresenting predetermined first information, said systemcomprising:breaking means for breaking desired one or more of saidblocks to form an aperture, so that the breakage state of the blocksrepresents second information which is different from said firstinformation; and reading means for optically reading said first andsecond information from said card type recording medium on the basis ofsaid different optical characteristics of the inks and presence of saidaperture.
 2. A system as defined in claim 1 wherein said block patternrepresenting said first information is a collation pattern for verifyingthat the card type recording medium is a true recording medium.
 3. Asystem as defined in claim 1 wherein said second information is variableinformation representing a state of use of the card type recordingmedium.
 4. A system as defined in claim 1 wherein said card typerecording medium further comprises a recording area made of a magneticrecording medium.
 5. A system as defined in claim 1 wherein said pluraltypes of inks are visually of the same color but exhibit differentcharacteristics to light of an invisible wavelength region.
 6. A systemas defined in claim 1 wherein said plural types of inks are visually ofthe same color at normal temperature but exhibit different opticalcharacteristics under a predetermined temperature condition.